U.S. patent application number 10/920997 was filed with the patent office on 2006-02-23 for planetary transmissions having a stationary member and three interconnected gear members.
Invention is credited to Norman K. Bucknor, Madhusudan Raghavan, Patrick B. Usoro.
Application Number | 20060040783 10/920997 |
Document ID | / |
Family ID | 35853731 |
Filed Date | 2006-02-23 |
United States Patent
Application |
20060040783 |
Kind Code |
A1 |
Raghavan; Madhusudan ; et
al. |
February 23, 2006 |
Planetary transmissions having a stationary member and three
interconnected gear members
Abstract
The family of transmissions has a plurality of members that can
be utilized in powertrains to provide at least eight forward speed
ratios and one reverse speed ratio. The transmission family members
include three planetary gear sets having seven torque-transmitting
mechanisms, one interconnecting member, and a grounded planetary
gear member. The powertrain includes an engine that is selectively
connectable to at least one of the planetary gear members and an
output member that is continuously connected with another one of
the planetary gear members. The seven torque-transmitting
mechanisms provide interconnections between various gear members,
the input shaft and the transmission housing, and are operated in
combinations of three to establish at least eight forward speed
ratios and at least one reverse speed ratio.
Inventors: |
Raghavan; Madhusudan; (West
Bloomfield, MI) ; Bucknor; Norman K.; (Troy, MI)
; Usoro; Patrick B.; (Troy, MI) |
Correspondence
Address: |
KATHRYN A. MARRA;General Motors Corporation
Mail Code 482-C23-B21 Legal Staff
P.O. Box 300
Detroit
MI
48265-3000
US
|
Family ID: |
35853731 |
Appl. No.: |
10/920997 |
Filed: |
August 18, 2004 |
Current U.S.
Class: |
475/275 |
Current CPC
Class: |
F16H 2200/0091 20130101;
F16H 3/666 20130101; F16H 2200/201 20130101; F16H 2200/006
20130101; F16H 2200/0069 20130101; F16H 3/66 20130101; F16H
2200/2048 20130101; F16H 2200/0073 20130101; F16H 2200/2097
20130101; F16H 2200/0065 20130101; F16H 2200/0086 20130101 |
Class at
Publication: |
475/275 |
International
Class: |
F16H 3/62 20060101
F16H003/62 |
Claims
1. A multi-speed transmission comprising: an input shaft; an output
shaft; first, second and third planetary gear sets each having
first, second and third members; said output shaft being
continuously interconnected with a member of said planetary gear
sets, and said input shaft not being continuously interconnected
with any member of said planetary gear sets; a first
interconnecting member continuously interconnecting said first
member of said first planetary gear set and said first member of
said second planetary gear set with said first member of said third
planetary gear set; said second member of said first planetary gear
set being continuously connected with a stationary member; a first
torque-transmitting mechanism selectively interconnecting a member
of said first or third planetary gear set with said input shaft; a
second torque-transmitting mechanism selectively interconnecting a
member of said second or third planetary gear set with said input
shaft; a third torque-transmitting mechanism selectively
interconnecting a member of said first, second or third planetary
gear set with said input shaft or with another member of said
first, second or third planetary gear set; a fourth
torque-transmitting mechanism selectively interconnecting a member
of said third planetary gear set with a member of said first or
second planetary gear set; a fifth torque-transmitting mechanism
selectively interconnecting a member of said second planetary gear
set with a member of said first or third planetary gear set; a
sixth torque-transmitting mechanism selectively interconnecting a
member of said second or third planetary gear set with another
member of said first, second or third planetary gear set or with
said stationary member; a seventh torque-transmitting mechanism
selectively interconnecting a member of said first, second or third
planetary gear set with another member of said first, second or
third planetary gear set, or with said stationary member; said
torque-transmitting mechanisms being engaged in combinations of
three to establish at least eight forward speed ratios and at least
one reverse speed ratio between said input shaft and said output
shaft.
2. The transmission defined in claim 1, wherein said first, second,
third, fourth and fifth torque-transmitting mechanisms comprise
clutches, and said sixth and seventh torque-transmitting mechanisms
comprise brakes.
3. The transmission defined in claim 1, wherein said first, second,
third, fourth, fifth and sixth torque-transmitting mechanisms
comprise clutches, and said seventh torque-transmitting mechanism
comprises a brake.
4. The transmission defined in claim 1, wherein said first, second,
third, fourth, fifth, sixth and seventh torque-transmitting
mechanisms comprise clutches.
5. The transmission defined in claim 1, wherein said first, second,
third, fourth, fifth and seventh torque-transmitting mechanisms
comprise clutches, and said sixth torque-transmitting mechanism
comprises a brake.
6. The transmission defined in claim 1, wherein planet carrier
assembly members of each of said planetary gear sets are
single-pinion carriers.
7. The transmission defined in claim 1, wherein at least one planet
carrier assembly member of said planetary gear sets is a
double-pinion carrier.
8. A multi-speed transmission comprising: an input shaft; an output
shaft; a planetary gear arrangement having first, second and third
planetary gear sets, each planetary gear set having first, second
and third members; said output shaft being continuously
interconnected with a member of said planetary gear sets, and said
input shaft not being continuously interconnected with any member
of said planetary gear sets; a first interconnecting member
continuously interconnecting said first member of said first
planetary gear set and said first member of said second planetary
gear set with said first member of said third planetary gear set;
said second member of said first planetary gear set being
continuously connected with a stationary member; and seven
torque-transmitting mechanisms for selectively interconnecting said
members of said planetary gear sets with said input shaft, with
said stationary member or with other members of said planetary gear
sets, said seven torque-transmitting mechanisms being engaged in
combinations of three to establish at least eight forward speed
ratios and at least one reverse speed ratio between said input
shaft and said output shaft.
9. The transmission defined in claim 8, wherein a first of said
seven torque-transmitting mechanisms is operable for selectively
interconnecting a member of said first or third planetary gear set
with said input shaft.
10. The transmission defined in claim 8, wherein a second of said
seven torque-transmitting mechanisms is operable for selectively
interconnecting a member of said second or third planetary gear set
with said input shaft.
11. The transmission defined in claim 8, wherein a third of said
seven torque-transmitting mechanisms is selectively operable for
interconnecting a member of said first, second or third planetary
gear set with said input shaft or with another member of said
first, second or third planetary gear set.
12. The transmission defined in claim 8, wherein a fourth of said
seven torque-transmitting mechanisms is selectively operable for
interconnecting a member of said third planetary gear set with a
member of said first or second planetary gear set.
13. The transmission defined in claim 8, wherein a fifth of said
seven torque-transmitting mechanisms is selectively operable for
interconnecting a member of said second planetary gear set with a
member of said first or third planetary gear set.
14. The transmission defined in claim 8, wherein a sixth of said
seven torque-transmitting mechanisms selectively interconnects a
member of said second or third planetary gear set with another
member of said first, second or third planetary gear set or with
said stationary member.
15. The transmission defined in claim 8, wherein a seventh of said
seven torque-transmitting mechanisms selectively interconnects a
member of said first, second or third planetary gear set with
another member of said first, second or third planetary gear set,
or with said stationary member.
16. The transmission defined in claim 8, wherein planet carrier
assembly members of each of said planetary gear sets are
single-pinion carriers.
17. The transmission defined in claim 8, wherein at least one
planet carrier assembly member of said planetary gear sets is a
double-pinion carrier.
Description
TECHNICAL FIELD
[0001] The present invention relates to a family of power
transmissions having three planetary gear sets that are controlled
by seven torque-transmitting devices to provide at least eight
forward speed ratios and at least one reverse speed ratio.
BACKGROUND OF THE INVENTION
[0002] Passenger vehicles include a powertrain that is comprised of
an engine, multi-speed transmission, and a differential or final
drive. The multi-speed transmission increases the overall operating
range of the vehicle by permitting the engine to operate through
its torque range a number of times. The number of forward speed
ratios that are available in the transmission determines the number
of times the engine torque range is repeated. Early automatic
transmissions had two speed ranges. This severely limited the
overall speed range of the vehicle and therefore required a
relatively large engine that could produce a wide speed and torque
range. This resulted in the engine operating at a specific fuel
consumption point during cruising, other than the most efficient
point. Therefore, manually-shifted (countershaft transmissions)
were the most popular.
[0003] With the advent of three- and four-speed automatic
transmissions, the automatic shifting (planetary gear) transmission
increased in popularity with the motoring public. These
transmissions improved the operating performance and fuel economy
of the vehicle. The increased number of speed ratios reduces the
step size between ratios and therefore improves the shift quality
of the transmission by making the ratio interchanges substantially
imperceptible to the operator under normal vehicle
acceleration.
[0004] It has been suggested that the number of forward speed
ratios be increased to six or more. Six-speed transmissions are
disclosed in U.S. Pat. No. 4,070,927 issued to Polak on Jan. 31,
1978; and U.S. Pat. No. 6,422,969 issued to Raghavan and Usoro on
Jul. 23, 2002.
[0005] Six-speed transmissions offer several advantages over four-
and five-speed transmissions, including improved vehicle
acceleration and improved fuel economy. While many trucks employ
power transmissions having six or more forward speed ratios,
passenger cars are still manufactured with three- and four-speed
automatic transmissions and relatively few five or six-speed
devices due to the size and complexity of these transmissions.
[0006] Seven-speed transmissions are disclosed in U.S. Pat. No.
6,623,397 issued to Raghavan, Bucknor and Usoro. Eight speed
transmissions are disclosed in U.S. Pat. No. 6,425,841 issued to
Haka. The Haka transmission utilizes three planetary gear sets and
six torque transmitting devices, including two brakes and two
clutches, to provide eight forward speed ratios and a reverse speed
ratio. One of the planetary gear sets is positioned and operated to
establish two fixed speed input members for the remaining two
planetary gear sets. Seven-, eight- and nine-speed transmissions
provide further improvements in acceleration and fuel economy over
six-speed transmissions. However, like the six-speed transmissions
discussed above, the development of seven-, eight- and nine-speed
transmissions has been precluded because of complexity, size and
cost.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide an
improved family of transmissions having three planetary gear sets
controlled to provide at least eight forward speed ratios and at
least one reverse speed ratio.
[0008] In one aspect of the present invention, the family of
transmissions has three planetary gear sets, each of which includes
a first, second and third member, which members may comprise a sun
gear, a ring gear, or a planet carrier assembly member, in any
order.
[0009] In referring to the first, second and third gear sets in
this description and in the claims, these sets may be counted
"first" to "third" in any order in the drawings (i.e., left to
right, right to left, etc.).
[0010] In another aspect of the present invention, the planetary
gear sets may be of the single pinion-type or of the double
pinion-type.
[0011] In yet another aspect of the present invention, a first
member of the first planetary gear set is continuously
interconnected with a first member of the second planetary gear set
and a first member of the third planetary gear set through a first
interconnecting member.
[0012] In a further aspect of the present invention, a second
member of the first planetary gear set is continuously connected
with a stationary member.
[0013] In yet a further aspect of the invention, each family member
incorporates an output shaft which is continuously connected with
at least one member of the planetary gear sets, and an input shaft
which is not continuously connected with any member of the
planetary gear sets but is selectively connectable with at least
one member of the planetary gear sets through at least one of seven
torque-transmitting mechanisms.
[0014] In still a further aspect of the invention, a first
torque-transmitting mechanism, such as a clutch, selectively
interconnects a member of the first or third planetary gear set
with the input shaft.
[0015] In another aspect of the invention, a second
torque-transmitting mechanism, such as a clutch, selectively
interconnects a member of the second or third planetary gear set
with the input shaft.
[0016] In a still further aspect of the invention, a third
torque-transmitting mechanism, such as a clutch, selectively
interconnects a member of the first, second or third planetary gear
set with the input shaft or with another member of the first,
second or third planetary gear set.
[0017] In a still further aspect of the invention, a fourth
torque-transmitting mechanism, such as a clutch, selectively
interconnects a member of the third planetary gear set with a
member of the first or second planetary gear set.
[0018] In a still further aspect of the invention, a fifth
torque-transmitting mechanism, such as a clutch, selectively
connects a member of the second planetary gear set with a member of
the first or third planetary gear set.
[0019] In still another aspect of the invention, a sixth
torque-transmitting mechanism, such as a clutch, selectively
connects a member of the second or third planetary gear set with
another member of the first, second or third planetary gear set.
Alternatively, the sixth torque-transmitting mechanism, such as a
brake, selectively connects a member of the second or third
planetary gear set with a stationary member (transmission
case).
[0020] In still another aspect of the invention, a seventh
torque-transmitting mechanism, such as a clutch, selectively
interconnects a member of the first, second or third planetary gear
set with another member of the first, second or third planetary
gear set. Alternatively, the seventh torque-transmitting mechanism,
such as a brake, selectively connects a member of the first, second
or third planetary gear set with the stationary member
(transmission case).
[0021] In still another aspect of the invention, the seven
torque-transmitting mechanisms are selectively engageable in
combinations of three to yield at least eight forward speed ratios
and at least one reverse speed ratio.
[0022] The above objects and other objects, features, and
advantages of the present invention are readily apparent from the
following detailed description of the best modes for carrying out
the invention when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1a is a schematic representation of a powertrain
including a planetary transmission incorporating a family member of
the present invention;
[0024] FIG. 1b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 1a;
[0025] FIG. 2a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0026] FIG. 2b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 2a;
[0027] FIG. 3a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0028] FIG. 3b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 3a;
[0029] FIG. 4a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0030] FIG. 4b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 4a;
[0031] FIG. 5a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0032] FIG. 5b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 5a;
[0033] FIG. 6a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0034] FIG. 6b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 6a;
[0035] FIG. 7a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0036] FIG. 7b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 7a;
[0037] FIG. 8a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0038] FIG. 8b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 8a;
[0039] FIG. 9a is a schematic representation of a powertrain having
a planetary transmission incorporating another family member of the
present invention;
[0040] FIG. 9b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 9a;
[0041] FIG. 10a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention;
[0042] FIG. 10b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 10a;
[0043] FIG. 11a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention;
[0044] FIG. 11b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 11a;
[0045] FIG. 12a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention;
[0046] FIG. 12b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 12a;
[0047] FIG. 13a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention;
[0048] FIG. 13b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 13a;
[0049] FIG. 14a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention;
[0050] FIG. 14b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 14a;
[0051] FIG. 15a is a schematic representation of a powertrain
having a planetary transmission incorporating another family member
of the present invention; and
[0052] FIG. 15b is a truth table and chart depicting some of the
operating characteristics of the powertrain shown in FIG. 15a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring to the drawings, wherein like characters represent
the same or corresponding parts throughout the several views, there
is shown in FIG. 1a a powertrain 10 having a conventional engine
12, a planetary transmission 14, and a conventional final drive
mechanism 16.
[0054] The planetary transmission 14 includes an input shaft 17
continuously connected with the engine 12, a planetary gear
arrangement 18, and an output shaft 19 continuously connected with
the final drive mechanism 16. The planetary gear arrangement 18
includes three planetary gear sets 20, 30 and 40.
[0055] The planetary gear set 20 includes a sun gear member 22, a
ring gear member 24, and a planet carrier assembly 26. The planet
carrier assembly 26 includes a plurality of pinion gears 27
rotatably mounted on a carrier member 29 and disposed in meshing
relationship with both the sun gear member 22 and the ring gear
member 24.
[0056] The planetary gear set 30 includes a sun gear member 32, a
ring gear member 34, and a planet carrier assembly member 36. The
planet carrier assembly member 36 includes a plurality of pinion
gears 37 rotatably mounted on a carrier member 39 and disposed in
meshing relationship with both the sun gear member 32 and the ring
gear member 34.
[0057] The planetary gear set 40 includes a sun gear member 42, a
ring gear member 44, and a planet carrier assembly member 46. The
planet carrier assembly member 46 includes a plurality of pinion
gears 47 rotatably mounted on a carrier member 49 and disposed in
meshing relationship with both the sun gear member 42 and the ring
gear member 44.
[0058] The planetary gear arrangement also includes seven
torque-transmitting mechanisms 50, 52, 54, 56, 57, 58 and 59. The
torque-transmitting mechanisms 50, 52, 54, 56 and 57 are
rotating-type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 58 and 59 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0059] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 44. The ring gear member 24 is
continuously connected with the planet carrier assembly member 36
and the sun gear member 42 through the interconnecting member 70.
The sun gear member 22 is continuously connected with the
transmission housing 60.
[0060] The ring gear member 34 is selectively connectable with the
input shaft 17 through the clutch 50. The sun gear member 32 is
selectively connectable with the input shaft 17 through the clutch
52. The planet carrier assembly member 46 is selectively
connectable with the input shaft 17 through the clutch 54. The
planet carrier assembly member 26 is selectively connectable with
the ring gear member 34 through the clutch 56. The planet carrier
assembly member 26 is selectively connectable with the planet
carrier assembly member 46 through the clutch 57. The ring gear
member 34 is selectively connectable with the transmission housing
60 through the brake 58. The planet carrier assembly member 46 is
selectively connectable with the transmission housing 60 through
the brake 59.
[0061] As shown in FIG. 1b, and in particular the truth table
disclosed therein, the torque-transmitting mechanisms are
selectively engaged in combinations of three to provide eight
forward speed ratios and four reverse speed ratios.
[0062] The reverse speed ratio is established with the engagement
of the clutch 52 and the brakes 58, 59. The clutch 52 connects the
sun gear member 32 with the input shaft 17. The brake 58 connects
the ring gear member 34 with the transmission housing 60. The brake
59 connects the planet carrier assembly member 46 with the
transmission housing 60. The sun gear member 22, ring gear member
34 and planet carrier assembly member 46 do not rotate. The ring
gear member 24 rotates at the same speed as the planet carrier
assembly member 36 and the sun gear member 42. The sun gear member
32 rotates at the same speed as the input shaft 17. The speed of
the planet carrier assembly member 36 is determined from the speed
of the sun gear member 32 and the ring gear/sun gear tooth ratio of
the planetary gear set 30. The ring gear member 44 rotates at the
same speed as the output shaft 19. The ring gear member 44, and
therefore the output shaft 19, rotates at a speed determined from
the speed of the sun gear member 42 and the ring gear/sun gear
tooth ratio of the planetary gear set 40. The numerical value of
the reverse speed ratio is determined utilizing the ring gear/sun
gear tooth ratios of the planetary gear sets 30 and 40.
[0063] The first extra reverse speed ratio (R') is established with
the engagement of the clutches 52, 56 and the brake 59. The clutch
52 connects the sun gear member 32 with the input shaft 17. The
clutch 56 connects the planet carrier assembly member 26 with the
ring gear member 34. The brake 59 connects the planet carrier
assembly member 46 with the transmission housing 60. The sun gear
member 22 does not rotate. The planet carrier assembly member 26
rotates at the same speed as the ring gear member 34. The ring gear
member 24 rotates at the same speed as the planet carrier assembly
member 36 and the sun gear member 42. The speed of the planet
carrier assembly member 26 is determined from the speed of the ring
gear member 24 and the ring gear/sun gear tooth ratio of the
planetary gear set 20. The sun gear member 32 rotates at the same
speed as the input shaft 17. The speed of the planet carrier
assembly member 36 is determined from the speed of the ring gear
member 34, the speed of the sun gear member 32, and the ring
gear/sun gear tooth ratio of the planetary gear set 30. The planet
carrier assembly member 46 does not rotate. The ring gear member 44
rotates at the same speed as the output shaft 19. The ring gear
member 44, and therefore the output shaft 19, rotates at a speed
determined from the speed of the sun gear member 42 and the ring
gear/sun gear tooth ratio of the planetary gear set 40. The
numerical value of the first extra reverse speed ratio (R') is
determined utilizing the ring gear/sun gear tooth ratios of the
planetary gear sets 20, 30 and 40.
[0064] The second extra reverse speed ratio (R'') is established
with the engagement of the clutches 50, 52 and the brake 59. The
clutch 50 connects the ring gear member 34 with the input shaft 17.
The clutch 52 connects the sun gear member 32 with the input shaft
17. The brake 59 connects the planet carrier assembly member 46
with the transmission housing 60. The sun gear member 22 does not
rotate. The ring gear member 24, planetary gear set 30 and sun gear
member 42 rotate at the same speed as the input shaft 17. The
planet carrier assembly member 46 does not rotate. The ring gear
member 44 rotates at the same speed as the output shaft 19. The
ring gear member 44, and therefore the output shaft 19, rotates at
a speed determined from the speed of the sun gear member 42 and the
ring gear/sun gear tooth ratio of the planetary gear set 40. The
numerical value of the second extra reverse speed ratio (R'') is
determined utilizing the ring gear/sun gear tooth ratio of the
planetary gear set 40.
[0065] The third extra reverse speed ratio (R''') is established
with the engagement of the clutches 50, 56 and the brake 59. The
clutch 50 connects the ring gear member 34 with the input shaft 17.
The clutch 56 connects the planet carrier assembly member 26 with
the ring gear member 34. The brake 59 connects the planet carrier
assembly member 46 with the transmission housing 60. The sun gear
member 22 does not rotate. The planet carrier assembly member 26
and ring gear member 34 rotate at the speed as the input shaft 17.
The ring gear member 24 rotates at the same speed as the planet
carrier assembly member 36 and the sun gear member 42. The ring
gear member 24 rotates at a speed determined from the speed of the
planet carrier assembly member 26 and the ring gear/sun gear tooth
ratio of the planetary gear set 20. The planet carrier assembly
member 46 does not rotate. The ring gear member 44 rotates at the
same speed as the output shaft 19. The ring gear member 44, and
therefore the output shaft 19, rotates at a speed determined from
the speed of the sun gear member 42 and the ring gear/sun gear
tooth ratio of the planetary gear set 40. The numerical value of
the third extra reverse speed ratio (R''') is determined utilizing
the ring gear/sun gear tooth ratios of the planetary gear sets 20
and 40.
[0066] The first forward speed ratio is established with the
engagement of the clutches 52, 57, and the brake 58. The clutch 52
connects the sun gear member 32 with the input shaft 17. The clutch
57 connects the planet carrier assembly member 26 with the planet
carrier assembly member 46. The brake 58 connects the ring gear
member 34 with the transmission housing 60. The sun gear member 22
does not rotate. The planet carrier assembly member 26 rotates at
the same speed as the planet carrier assembly member 46. The ring
gear member 24 rotates at the same speed as the planet carrier
assembly member 36 and the sun gear member 42. The speed of the
planet carrier assembly member 26 is determined from the speed of
the ring gear member 24 and the ring gear/sun gear tooth ratio of
the planetary gear set 20. The sun gear member 32 rotates at the
same speed as the input shaft 17. The ring gear member 34 does not
rotate. The speed of the planet carrier assembly member 36 is
determined from the speed of the sun gear member 32 and the ring
gear/sun gear tooth ratio of the planetary gear set 30. The ring
gear member 44 rotates at the same speed as the output shaft 19.
The ring gear member 44, and therefore the output shaft 19, rotates
at a speed determined from the speed of the planet carrier assembly
member 46, the speed of the sun gear member 42, and the ring
gear/sun gear tooth ratio of the planetary gear set 40. The
numerical value of the first forward speed ratio is determined
utilizing the ring gear/sun gear tooth ratios of the planetary gear
sets 20, 30 and 40.
[0067] The second forward speed ratio is established with the
engagement of the clutches 52, 56 and 57. The clutch 52 connects
the sun gear member 32 with the input shaft 17. The clutch 56
connects the planet carrier assembly member 26 with the ring gear
member 34. The clutch 57 connects the planet carrier assembly
member 26 with the planet carrier assembly member 46. The sun gear
member 22 does not rotate. The planet carrier assembly member 26
rotates at the same speed as the ring gear member 34 and the planet
carrier assembly member 46. The ring gear member 24 rotates at the
same speed as the planet carrier assembly member 36 and the sun
gear member 42. The speed of the planet carrier assembly member 26
is determined from the speed of the ring gear member 24 and the
ring gear/sun gear tooth ratio of the planetary gear set 20. The
speed of the planet carrier assembly member 36 is determined from
the speed of the ring gear member 34, the speed of the sun gear
member 32, and the ring gear/sun gear tooth ratio of the planetary
gear set 30. The ring gear member 44 rotates at the same speed as
the output shaft 19. The speed of the ring gear member 44, and
therefore the output shaft 19, is determined from the speed of the
planet carrier assembly member 46, the speed of the sun gear member
42, and the ring gear/sun gear tooth ratio of the planetary gear
set 40. The numerical value of the second forward speed ratio is
determined utilizing the ring gear/sun gear tooth ratios of the
planetary gear sets 20, 30 and 40.
[0068] The third forward speed ratio is established with the
engagement of the clutches 50, 52 and 57. The clutch 50 connects
the ring gear member 34 with the input shaft 17. The clutch 52
connects the sun gear member 32 with the input shaft 17. The clutch
57 connects the planet carrier assembly member 26 with the planet
carrier assembly member 46. The sun gear member 22 does not rotate.
The planet carrier assembly member 26 rotates at the same speed as
the planet carrier assembly member 46. The ring gear member 24,
planetary gear set 30 and planet carrier assembly member 46 rotate
at the same speed as the input shaft 17. The speed of the planet
carrier assembly member 26 is determined from the speed of the
speed of the ring gear member 24 and the ring gear/sun gear tooth
ratio of the planetary gear set 20. The ring gear member 44 rotates
at the same speed as the output shaft 19. The ring gear member 44,
and therefore the output shaft 19, rotates at a speed determined
from the speed of the planet carrier assembly member 46, the speed
of the sun gear member 42, and the ring gear/sun gear tooth ratio
of the planetary gear set 40. The numerical value of the third
forward speed ratio is determined utilizing the ring gear/sun gear
tooth ratios of the planetary gear sets 20 and 40.
[0069] The fourth forward speed ratio is established with the
engagement of the clutches 50, 54 and 57. The clutch 50 connects
the ring gear member 34 with the input shaft 17. The clutch 54
connects the planet carrier assembly member 46 with the input shaft
17. The clutch 57 connects the planet carrier assembly member 26
with the planet carrier assembly member 46. The sun gear member 22
does not rotate. The planet carrier assembly members 26, 46 and the
ring gear member 34 rotate at the same speed as the input shaft 17.
The ring gear member 24 rotates at the same speed as the planet
carrier assembly member 36 and the sun gear member 42. The speed of
the ring gear member 24 is determined from the speed of the planet
carrier assembly member 26 and the ring gear/sun gear tooth ratio
of the planetary gear set 20. The ring gear member 44 rotates at
the same speed as the output shaft 19. The ring gear member 44, and
therefore the output shaft 19, rotates at a speed determined from
the speed of the planet carrier assembly member 46, the speed of
the sun gear member 42, and the ring gear/sun gear tooth ratio of
the planetary gear set 40. The numerical value of the fourth
forward speed ratio is determined utilizing the ring gear/sun gear
tooth ratios of the planetary gear sets 20 and 40.
[0070] The fifth forward speed ratio is established with the
engagement of the clutches 50, 52 and 54. In this configuration,
the input shaft 17 is directly connected to the output shaft 19.
The numerical value of the fifth forward speed ratio is 1.
[0071] The sixth forward speed ratio is established with the
engagement of the clutches 52, 54 and 56. The clutch 52 connects
the sun gear member 32 with the input shaft 17. The clutch 54
connects the planet carrier assembly member 46 with the input shaft
17. The clutch 56 connects the planet carrier assembly member 26
with the ring gear member 34. The sun gear member 22 does not
rotate. The planet carrier assembly member 26 rotates at the same
speed as the ring gear member 34. The ring gear member 24 rotates
at the same speed as the planet carrier assembly member 36 and the
sun gear member 42. The speed of the planet carrier assembly member
26 is determined from the speed of the ring gear member 24 and the
ring gear/sun gear tooth ratio of the planetary gear set 20. The
sun gear member 32 and planet carrier assembly member 46 rotate at
the same speed as the input. The speed of the planet carrier
assembly member 36 is determined from the speed of the ring gear
member 34, the speed of the sun gear member 32, and the ring
gear/sun gear tooth ratio of the planetary gear set 30. The ring
gear member 44 rotates at the same speed as the output shaft 19.
The ring gear member 44, and therefore the output shaft 19, rotates
at a speed determined from the speed of the planet carrier assembly
member 46, the speed of the sun gear member 42, and the ring
gear/sun gear tooth ratio of the planetary gear set 40. The
numerical value of the sixth forward speed ratio is determined
utilizing the ring gear/sun gear tooth ratios of the planetary gear
sets 20, 30 and 40.
[0072] The seventh forward speed ratio is established with the
engagement of the clutches 52, 54 and the brake 58. The clutch 52
connects the sun gear member 32 with the input shaft 17. The clutch
54 connects the planet carrier assembly member 46 with the input
shaft 17. The brake 58 connects the ring gear member 34 with the
transmission housing 60. The sun gear member 22 and ring gear
member 34 do not rotate. The ring gear member 24 rotates at the
same speed as the planet carrier assembly member 36 and the sun
gear member 42. The sun gear member 32 and planet carrier assembly
member 46 rotate at the same speed as the input shaft 17. The speed
of the planet carrier assembly member 36 is determined from the
speed of the sun gear member 32 and the ring gear/sun gear tooth
ratio of the planetary gear set 30. The ring gear member 44 rotates
at the same speed as the output shaft 19. The ring gear member 44,
and therefore the output shaft 19, rotates at a speed determined
from the speed of the planet carrier assembly member 46, the speed
of the sun gear member 42, and the ring gear/sun gear tooth ratio
of the planetary gear set 40. The numerical value of the seventh
forward speed ratio is determined utilizing the ring gear/sun gear
tooth ratios of the planetary gear sets 30 and 40.
[0073] The eighth forward speed ratio is established with the
engagement of the clutches 54, 56 and the brake 58. The clutch 54
connects the planet carrier assembly member 46 with the input shaft
17. The clutch 56 connects the planet carrier assembly member 26
with the ring gear member 34. The brake 58 connects the ring gear
member 34 with the transmission housing 60. The planetary gear sets
20, 30 and sun gear member 42 do not rotate. The planet carrier
assembly member 46 rotates at the same speed as the input shaft 17.
The ring gear member 44 rotates at the same speed as the output
shaft 19. The ring gear member 44, and therefore the output shaft
19, rotates at a speed determined from the speed of the planet
carrier assembly member 46 and the ring gear/sun gear tooth ratio
of the planetary gear set 40. The numerical value of the eighth
forward speed ratio is determined utilizing the ring gear/sun gear
tooth ratio of the planetary gear set 40.
[0074] As set forth above, the engagement schedule for the
torque-transmitting mechanisms is shown in the truth table of FIG.
1b. This truth table also provides an example of speed ratios that
are available utilizing the ring gear/sun gear tooth ratios given
by way of example in FIG. 1b. The N.sub.R1/N.sub.S1 value is the
tooth ratio of the planetary gear set 20; the N.sub.R2/N.sub.S2
value is the tooth ratio of the planetary gear set 30; and the
N.sub.R3/N.sub.S3 value is the tooth ratio of the planetary gear
set 40. Also, the chart of FIG. 1b describes the ratio steps that
are attained utilizing the sample of tooth ratios given. For
example, the step ratio between the first and second forward speed
ratios is 1.82, while the step ratio between the reverse and first
forward ratio is -1.05.
[0075] FIG. 2a shows a powertrain 110 having a conventional engine
12, a planetary transmission 114, and a conventional final drive
mechanism 16.
[0076] The planetary transmission 114 includes an input shaft 17
continuously connected with the engine 12, a planetary gear
arrangement 118, and an output shaft 19 continuously connected with
the final drive mechanism 16. The planetary gear arrangement 118
includes three planetary gear sets 120, 130 and 140.
[0077] The planetary gear set 120 includes a sun gear member 122, a
ring gear member 124, and a planet carrier assembly 126. The planet
carrier assembly 126 includes a plurality of pinion gears 127
rotatably mounted on a carrier member 129 and disposed in meshing
relationship with both the sun gear member 122 and the ring gear
member 124.
[0078] The planetary gear set 130 includes a sun gear member 132, a
ring gear member 134, and a planet carrier assembly member 136. The
planet carrier assembly member 136 includes a plurality of pinion
gears 137 rotatably mounted on a carrier member 139 and disposed in
meshing relationship with both the sun gear member 132 and the ring
gear member 134.
[0079] The planetary gear set 140 includes a sun gear member 142, a
ring gear member 144, and a planet carrier assembly member 146. The
planet carrier assembly member 146 includes a plurality of pinion
gears 147 rotatably mounted on a carrier member 149 and disposed in
meshing relationship with both the sun gear member 142 and the ring
gear member 144.
[0080] The planetary gear arrangement 118 also includes seven
torque-transmitting mechanisms 150, 152, 154, 156, 157, 158 and
159. The torque-transmitting mechanisms 150, 152, 154, 156 and 157
are rotating-type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 158 and 159 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0081] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 144. The planet carrier
assembly member 126 is continuously connected with the ring gear
member 134 and the sun gear member 142 through the interconnecting
member 170. The sun gear member 122 is continuously connected with
the transmission housing 160.
[0082] The ring gear member 124 is selectively connectable with the
input shaft 17 through the clutch 150. The planet carrier assembly
member 146 is selectively connectable with the input shaft 17
through the clutch 152. The sun gear member 132 is selectively
connectable with the input shaft 17 through the clutch 154. The
ring gear member 124 is selectively connectable with the planet
carrier assembly member 136 through the clutch 156. The planet
carrier assembly member 136 is selectively connectable with the
planet carrier assembly member 146 through the clutch 157. The ring
gear member 124 is selectively connectable with the transmission
housing 160 through the brake 158. The planet carrier assembly
member 146 is selectively connectable with the transmission housing
160 through the brake 159.
[0083] The truth table of FIG. 2b describes the engagement sequence
utilized to provide eight forward speed ratios and two reverse
speed ratios in the planetary gear arrangement 118 shown in FIG.
2a.
[0084] The truth tables given in FIGS. 2b, 3b, 4b, 5b, 6b, 7b, 8b,
9b, 10b, 11b, 12b, 13b, 14b and 15b show the engagement sequences
for the torque-transmitting mechanisms to provide at least eight
forward speed ratios and at least one reverse ratio. As shown and
described above for the configuration in FIG. 1a, those skilled in
the art will understand from the respective truth tables how the
speed ratios are established through the planetary gear sets
identified in the written description.
[0085] As set forth above, the truth table of FIG. 2b describes the
engagement sequence of the torque-transmitting mechanisms utilized
to provide two reverse drive ratios and eight forward speed ratios.
The truth table also provides an example of the ratios that can be
attained with the family members shown in FIG. 2a utilizing the
sample tooth ratios given in FIG. 2b. The N.sub.R1/N.sub.S1 value
is the tooth ratio of the planetary gear set 120; the
N.sub.R2/N.sub.S2 value is the tooth ratio of the planetary gear
set 130; and the N.sub.R3/N.sub.S3 value is the tooth ratio of the
planetary gear set 140. Also shown in FIG. 2b are the ratio steps
between single step ratios in the forward direction as well as the
reverse to first step ratio. For example, the first to second step
ratio is 2.48.
[0086] Turning to FIG. 3a, a powertrain 210 includes the engine 12,
a planetary transmission 214, and a final drive mechanism 16. The
planetary transmission 214 includes an input shaft 17 continuously
connected with the engine 12, a planetary gear arrangement 218, and
an output shaft 19 continuously connected with the final drive
mechanism 16. The planetary gear arrangement 218 includes three
planetary gear sets 220, 230 and 240.
[0087] The planetary gear set 220 includes a sun gear member 222, a
ring gear member 224, and a planet carrier assembly 226. The planet
carrier assembly 226 includes a plurality of pinion gears 227
rotatably mounted on a carrier member 229 and disposed in meshing
relationship with both the sun gear member 222 and the ring gear
member 224.
[0088] The planetary gear set 230 includes a sun gear member 232, a
ring gear member 234, and a planet carrier assembly member 236. The
planet carrier assembly member 236 includes a plurality of pinion
gears 237 rotatably mounted on a carrier member 239 and disposed in
meshing relationship with both the sun gear member 232 and the ring
gear member 234.
[0089] The planetary gear set 240 includes a sun gear member 242, a
ring gear member 244, and a planet carrier assembly member 246. The
planet carrier assembly member 246 includes a plurality of pinion
gears 247 rotatably mounted on a carrier member 249 and disposed in
meshing relationship with both the sun gear member 242 and the ring
gear member 244.
[0090] The planetary gear arrangement 218 also includes seven
torque-transmitting mechanisms 250, 252, 254, 256, 257, 258 and
259. The torque-transmitting mechanisms 250, 252, 254, 256, 257 and
258 are rotating type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanism 259 is a
stationary-type torque transmitting mechanism, commonly termed
brake or reaction clutch.
[0091] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 244. The ring gear member 224
is continuously connected with the planet carrier assembly members
236 and 246 through the interconnecting member 270. The sun gear
member 222 is continuously connected with the transmission housing
260.
[0092] The ring gear member 234 is selectively connectable with the
input shaft 17 through the clutch 250. The sun gear member 232 is
selectively connectable with the input shaft 17 through the clutch
252. The sun gear member 242 is selectively connectable with the
input shaft 17 through the clutch 254. The planet carrier assembly
member 226 is selectively connectable with the ring gear member 234
through the clutch 256. The planet carrier assembly member 226 is
selectively connectable with the ring gear member 244 through the
clutch 257. The ring gear member 244 is selectively connectable
with the planet carrier assembly member 246 through the clutch 258.
The ring gear member 234 is selectively connectable with the
transmission housing 260 through the brake 259.
[0093] As shown in the truth table in FIG. 3b, the
torque-transmitting mechanisms are engaged in combinations of three
to establish eight forward speed ratios and one reverse speed
ratio, as well as extra third, fourth and fifth forward speed
ratios.
[0094] As previously set forth, the truth table of FIG. 3b
describes the combinations of engagements utilized for the forward
and reverse speed ratios. The truth table also provides an example
of speed ratios that are available with the family member described
above. These examples of speed ratios are determined utilizing the
tooth ratios given in FIG. 3b. The N.sub.R1/N.sub.S1 value is the
tooth ratio of the planetary gear set 220; the N.sub.R2/N.sub.S2
value is the tooth ratio of the planetary gear set 230; and the
N.sub.R3/N.sub.S3 value is the tooth ratio of the planetary gear
set 240. Also depicted in FIG. 3b is a chart representing the ratio
steps between adjacent forward speed ratios and between the first
and reverse speed ratio. For example, the first to second ratio
interchange has a step of 1.72.
[0095] A powertrain 310, shown in FIG. 4a, includes the engine 12,
a planetary transmission 314, and the final drive mechanism 16. The
planetary transmission 314 includes an input shaft 17 continuously
connected with the engine 12, a planetary gear arrangement 318, and
an output shaft 19 continuously connected with the final drive
mechanism 16. The planetary gear arrangement 318 includes three
planetary gear sets 320, 330 and 340.
[0096] The planetary gear set 320 includes a sun gear member 322, a
ring gear member 324, and a planet carrier assembly member 326. The
planet carrier assembly member 326 includes a plurality of pinion
gears 327 rotatably mounted on a carrier member 329 and disposed in
meshing relationship with both the sun gear member 322 and the ring
gear member 324.
[0097] The planetary gear set 330 includes a sun gear member 332, a
ring gear member 334, and a planet carrier assembly member 336. The
planet carrier assembly member 336 includes a plurality of pinion
gears 337 rotatably mounted on a carrier member 339 and disposed in
meshing relationship with both the sun gear member 332 and the ring
gear member 334.
[0098] The planetary gear set 340 includes a sun gear member 342, a
ring gear member 344, and a planet carrier assembly member 346. The
planet carrier assembly member 346 includes a plurality of pinion
gears 347 rotatably mounted on a carrier member 349 and disposed in
meshing relationship with both the sun gear member 342 and the ring
gear member 344.
[0099] The planetary gear arrangement 318 also includes seven
torque-transmitting mechanisms 350, 352, 354, 356, 357, 358 and
359. The torque-transmitting mechanisms 350, 352, 354, 356 and 357
are rotating type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 358 and 359 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0100] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 344. The ring gear member 324
is continuously connected with the sun gear members 332 and 342
through the interconnecting member 370. The planet carrier assembly
member 326 is continuously connected with the transmission housing
360.
[0101] The sun gear member 322 is selectively connectable with the
input shaft 17 through the clutch 350. The planet carrier assembly
member 336 is selectively connectable with the input shaft 17
through the clutch 352. The ring gear member 334 is selectively
connectable with the input shaft 17 through the clutch 354. The
planet carrier assembly member 336 is selectively connectable with
the planet carrier assembly member 346 through the clutch 356. The
planet carrier assembly member 336 is selectively connectable with
the ring gear member 344 through the clutch 357. The sun gear
member 322 is selectively connectable with the transmission housing
360 through the brake 358. The planet carrier assembly member 346
is selectively connectable with the transmission housing 360
through the brake 359.
[0102] The truth table shown in FIG. 4b describes the engagement
combination and the engagement sequence necessary to provide two
reverse drive ratios and eight forward speed ratios, as well as
extra fourth and fifth forward speed ratios. A sample of the
numerical values for the ratios is also provided in the truth table
of FIG. 4b. These values are determined utilizing the ring gear/sun
gear tooth ratios also given in FIG. 4b. The N.sub.R1/N.sub.S1
value is the tooth ratio for the planetary gear set 320; the
N.sub.R2/N.sub.S2 value is the tooth ratio for the planetary gear
set 330; and the N.sub.R3/N.sub.S3 value is the tooth ratio for the
planetary gear set 340. Also given in FIG. 4b is a chart describing
the step ratios between the adjacent forward speed ratios and the
reverse to first forward speed ratio. For example, the first to
second forward speed ratio step is 1.86.
[0103] A powertrain 410, shown in FIG. 5a, includes the engine 12,
a planetary transmission 414 and the final drive mechanism 16. The
planetary transmission 414 includes a planetary gear arrangement
418, input shaft 17 and output shaft 19. The planetary gear
arrangement 418 includes three simple planetary gear sets 420, 430
and 440.
[0104] The planetary gear set 420 includes a sun gear member 422, a
ring gear member 424, and a planet carrier assembly 426. The planet
carrier assembly 426 includes a plurality of pinion gears 427
rotatably mounted on a carrier member 429 and disposed in meshing
relationship with both the sun gear member 422 and the ring gear
member 424.
[0105] The planetary gear set 430 includes a sun gear member 432, a
ring gear member 434, and a planet carrier assembly member 436. The
planet carrier assembly member 436 includes a plurality of pinion
gears 437 rotatably mounted on a carrier member 439 and disposed in
meshing relationship with both the ring gear member 434 and the sun
gear member 432.
[0106] The planetary gear set 440 includes a sun gear member 442, a
ring gear member 444, and a planet carrier assembly member 446. The
planet carrier assembly member 446 includes a plurality of pinion
gears 447 rotatably mounted on a carrier member 449 and disposed in
meshing relationship with both the sun gear member 442 and the ring
gear member 444.
[0107] The planetary gear arrangement 418 also includes seven
torque-transmitting mechanisms 450, 452, 454, 456, 457, 458 and
459. The torque-transmitting mechanisms 450, 452, 454, 456 and 457
are rotating type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 458 and 459 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0108] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the planet carrier assembly member 446. The planet
carrier assembly member 426 is continuously connected with the ring
gear members 434 and 444 through the interconnecting member 470.
The sun gear member 422 is continuously connected with the
transmission housing 460.
[0109] The planet carrier assembly member 436 is selectively
connectable with the input shaft 17 through the clutch 450. The sun
gear member 442 is selectively connectable with the input shaft 17
through the clutch 452. The ring gear member 424 is selectively
connectable with the planet carrier assembly member 436 through the
clutch 454. The sun gear member 432 is selectively connectable with
the sun gear member 442 through the clutch 456. The sun gear member
432 is selectively connectable with the planet carrier assembly
member 446 through the clutch 457. The ring gear member 424 is
selectively connectable with the transmission housing 460 through
the brake 458. The planet carrier assembly member 436 is
selectively connectable with the transmission housing 460 through
the brake 459.
[0110] The truth table shown in FIG. 5b describes the engagement
combination and sequence of the torque-transmitting mechanisms 450,
452, 454, 456, 457, 458 and 459 that are employed to provide the
forward and reverse drive ratios.
[0111] Also given in the truth table of FIG. 5b is a set of
numerical values that are attainable with the present invention
utilizing the ring gear/sun gear tooth ratios shown. The
N.sub.R1/N.sub.S1 value is the tooth ratio of the planetary gear
set 420; the N.sub.R2/N.sub.S2 value is the tooth ratio of the
planetary gear set 430; and the N.sub.R3/N.sub.S3 value is the
tooth ratio of the planetary gear set 440.
[0112] FIG. 5b also provides a chart of the ratio steps between
adjacent forward ratios and between the reverse and first forward
ratio. For example, the ratio step between the first and second
forward ratios is 1.50.
[0113] A powertrain 510, shown in FIG. 6a, includes an engine 12, a
planetary gear transmission 514 and the final drive mechanism 16.
The planetary transmission 514 includes the input shaft 17, a
planetary gear arrangement 518 and the output shaft 19. The
planetary gear arrangement 518 includes three planetary gear sets
520, 530 and 540.
[0114] The planetary gear set 520 includes a sun gear member 522, a
ring gear member 524, and a planet carrier assembly 526. The planet
carrier assembly 526 includes a plurality of pinion gears 527
rotatably mounted on a carrier member 529 and disposed in meshing
relationship with both the sun gear member 522 and the ring gear
member 524.
[0115] The planetary gear set 530 includes a sun gear member 532, a
ring gear member 534, and a planet carrier assembly member 536. The
planet carrier assembly member 536 includes a plurality of pinion
gears 537 rotatably mounted on a carrier member 539 and disposed in
meshing relationship with both the sun gear member 532 and the ring
gear member 534.
[0116] The planetary gear set 540 includes a sun gear member 542, a
ring gear member 544, and a planet carrier assembly member 546. The
planet carrier assembly member 546 includes a plurality of pinion
gears 547 rotatably mounted on a carrier member 549 and disposed in
meshing relationship with both the sun gear member 542 and the ring
gear member 544.
[0117] The planetary gear arrangement 518 also includes seven
torque-transmitting mechanisms 550, 552, 554, 556, 557, 558 and
559. The torque-transmitting mechanisms 550, 552, 554, 556 and 557
are rotating type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 558 and 559 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0118] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 544. The planet carrier
assembly member 526 is continuously connected with the ring gear
member 534 and the sun gear member 542 through the interconnecting
member 570. The sun gear member 522 is continuously connected with
the transmission housing 560.
[0119] The ring gear member 524 is selectively connectable with the
input shaft 17 through the clutch 550. The sun gear member 532 is
selectively connectable with the input shaft 17 though the clutch
552. The ring gear member 524 is selectively connectable with the
planet carrier assembly member 536 through the clutch 554. The sun
gear member 532 is selectively connectable with the planet carrier
assembly member 546 through the clutch 556. The planet carrier
assembly member 536 is selectively connectable with the planet
carrier assembly member 546 through the clutch 557. The ring gear
member 524 is selectively connectable with the transmission housing
560 through the brake 558. The planet carrier assembly member 546
is selectively connectable with the transmission housing 560
through the brake 559.
[0120] The truth table shown in FIG. 6b describes the engagement
sequence and combination of the torque-transmitting mechanisms to
provide two reverse speed ratios and eight forward speed ratios, as
well as extra third and eighth forward speed ratios. The chart of
FIG. 6b describes the ratio steps between adjacent forward speed
ratios and the ratio step between the reverse and first forward
speed ratio.
[0121] The sample speed ratios given in the truth table are
determined utilizing the tooth ratio values also given in FIG. 6b.
The N.sub.R1/N.sub.S1 value is the tooth ratio of the planetary
gear set 520; the N.sub.R2/N.sub.S2 value is the tooth ratio of the
planetary gear set 530; and the N.sub.R3/N.sub.S3 value is the
tooth ratio of the planetary gear set 540.
[0122] A powertrain 610, shown in FIG. 7a, has the engine 12, a
planetary transmission 614 and the final drive mechanism 16. The
planetary transmission 614 includes the input shaft 17, a planetary
gear arrangement 618 and the output shaft 19. The planetary gear
arrangement 618 includes three planetary gear sets 620, 630 and
640.
[0123] The planetary gear set 620 includes a sun gear member 622, a
ring gear member 624, and a planet carrier assembly 626. The planet
carrier assembly 626 includes a plurality of pinion gears 627
rotatably mounted on a carrier member 629 and disposed in meshing
relationship with both the sun gear member 622 and the ring gear
member 624.
[0124] The planetary gear set 630 includes a sun gear member 632, a
ring gear member 634, and a planet carrier assembly member 636. The
planet carrier assembly member 636 includes a plurality of pinion
gears 637 rotatably mounted on a carrier member 639 and disposed in
meshing relationship with both the sun gear member 632 and the ring
gear member 634.
[0125] The planetary gear set 640 includes a sun gear member 642, a
ring gear member 644, and a planet carrier assembly member 646. The
planet carrier assembly member 646 includes a plurality of pinion
gears 647 rotatably mounted on a carrier member 649 and disposed in
meshing relationship with both the sun gear member 642 and the ring
gear member 644.
[0126] The planetary gear arrangement 618 also includes seven
torque-transmitting mechanisms 650, 652, 654, 656, 657, 658 and
659. The torque-transmitting mechanisms 650, 652, 654, 656 and 657
are rotating type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 658 and 659 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0127] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 644. The planet carrier
assembly member 626 is continuously connected with the ring gear
member 634 and the sun gear member 642 through the interconnecting
member 670. The ring gear member 624 is continuously connected with
the transmission housing 660.
[0128] The planet carrier assembly member 646 is selectively
connectable with the input shaft 17 through the clutch 650. The sun
gear member 632 is selectively connectable with the input shaft 17
through the clutch 652. The sun gear member 622 is selectively
connectable with the sun gear member 632 through the clutch 654.
The sun gear member 622 is selectively connectable with the planet
carrier assembly member 636 through the clutch 656. The planet
carrier assembly member 636 is selectively connectable with the
planet carrier assembly member 646 through the clutch 657. The sun
gear member 622 is selectively connectable with the transmission
housing 660 through the brake 658. The planet carrier assembly
member 646 is selectively connectable with the transmission housing
660 through the brake 659.
[0129] The truth table shown in FIG. 7b describes the combination
of torque-transmitting mechanism engagements that will provide two
reverse drive ratios and eight forward speed ratios (including the
extra seventh ratio), as well as the sequence of these engagements
and interchanges.
[0130] The ratio values given are by way of example and are
established utilizing the ring gear/sun gear tooth ratios given in
FIG. 7b. For example, the N.sub.R1/N.sub.S1 value is the tooth
ratio of the planetary gear set 620; the N.sub.R2/N.sub.S2 value is
the tooth ratio of the planetary gear set 630; and the
N.sub.R3/N.sub.S3 value is the tooth ratio of the planetary gear
set 640. The ratio steps between adjacent forward ratios and the
reverse to first ratio are also given in FIG. 7b.
[0131] A powertrain 710, shown in FIG. 8a, has the conventional
engine 12, a planetary transmission 714, and the conventional final
drive mechanism 16. The engine 12 is drivingly connected with the
planetary transmission 714 through the input shaft 17. The
planetary transmission 714 is drivingly connected with the final
drive mechanism 16 through the output shaft 19. The planetary
transmission 714 includes a planetary gear arrangement 718 that has
a first planetary gear set 720, a second planetary gear set 730,
and a third planetary gear set 740.
[0132] The planetary gear set 720 includes a sun gear member 722, a
ring gear member 724, and a planet carrier assembly 726. The planet
carrier assembly 726 includes a plurality of pinion gears 727
rotatably mounted on a carrier member 729. The pinion gears 727 are
disposed in meshing relationship with the sun gear member 722 and
the ring gear member 724.
[0133] The planetary gear set 730 includes a sun gear member 732, a
ring gear member 734, and a planet carrier assembly member 736. The
planet carrier assembly member 736 includes a plurality of pinion
gears 737 rotatably mounted on a carrier member 739 and disposed in
meshing relationship with both the sun gear member 732 and the ring
gear member 734.
[0134] The planetary gear set 740 includes a sun gear member 742, a
ring gear member 744, and a planet carrier assembly member 746. The
planet carrier assembly member 746 includes a plurality of pinion
gears 747 rotatably mounted on a carrier member 749 and disposed in
meshing relationship with both the sun gear member 742 and the ring
gear member 744.
[0135] The planetary gear arrangement 718 also includes seven
torque-transmitting mechanisms 750, 752, 754, 756, 757, 758 and
759. The torque-transmitting mechanisms 750, 752, 754, 756 and 757
are rotating type torque-transmitting mechanisms, commonly termed
clutches. The torque-transmitting mechanisms 758 and 759 are
stationary-type torque transmitting mechanisms, commonly termed
brakes or reaction clutches.
[0136] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 744. The ring gear member 724
is continuously connected with the ring gear member 734 and the sun
gear member 742 through the interconnecting member 770. The planet
carrier assembly member 726 is continuously connected with the
transmission housing 760.
[0137] The sun gear member 722 is selectively connectable with the
input shaft 17 through the clutch 750. The sun gear member 732 is
selectively connectable with the input shaft 17 through the clutch
752. The sun gear member 722 is selectively connectable with the
planet carrier assembly member 736 through the clutch 754. The
planet carrier assembly member 736 is selectively connectable with
the planet carrier assembly member 746 through the clutch 756. The
sun gear member 732 is selectively connectable with the planet
carrier assembly member 746 through the clutch 757. The sun gear
member 722 is selectively connectable with the transmission housing
760 through the brake 758. The planet carrier assembly member 746
is selectively connectable with the transmission housing 760
through the brake 759.
[0138] The truth table of FIG. 8b defines the torque-transmitting
mechanism engagement sequence utilized for each of the forward and
reverse speed ratios. Also given in the truth table is a set of
numerical values that are attainable with the present invention
utilizing the ring gear/sun gear tooth ratios given in FIG. 8b. The
N.sub.R1/N.sub.S1 value is the tooth ratio of the planetary gear
set 720; the N.sub.R2/N.sub.S2 value is the tooth ratio of the
planetary gear set 730; and the N.sub.R3/N.sub.S3 value is the
tooth ratio of the planetary gear set 740.
[0139] FIG. 8b also provides a chart of the ratio steps between
adjacent forward ratios and between the reverse and first forward
ratio. For example, the ratio step between the first and second
forward ratios is 1.93.
[0140] A powertrain 810, shown in FIG. 9a, has the conventional
engine 12, a planetary transmission 814, and the final drive
mechanism 16. The engine 12 is drivingly connected with the
planetary transmission 814 through the input shaft 17. The
planetary transmission 814 is drivingly connected with the final
drive mechanism 16 through the output shaft 19. The planetary
transmission 814 includes a planetary gear arrangement 818 that has
a first planetary gear set 820, a second planetary gear set 830,
and a third planetary gear set 840.
[0141] The planetary gear set 820 includes a sun gear member 822, a
ring gear member 824, and a planet carrier assembly 826. The planet
carrier assembly 826 includes a plurality of pinion gears 827
rotatably mounted on a carrier member 829 and disposed in meshing
relationship with the sun gear member 822 and the ring gear member
824.
[0142] The planetary gear set 830 includes a sun gear member 832, a
ring gear member 834, and a planet carrier assembly member 836. The
planet carrier assembly member 836 includes a plurality of pinion
gears 837 rotatably mounted on a carrier member 839 and disposed in
meshing relationship with both the sun gear member 832 and the ring
gear member 834.
[0143] The planetary gear set 840 includes a sun gear member 842, a
ring gear member 844, and a planet carrier assembly member 846. The
planet carrier assembly member 846 includes a plurality of pinion
gears 847 rotatably mounted on a carrier member 849 and disposed in
meshing relationship with both the ring gear member 844 and the sun
gear member 842.
[0144] The planetary gear arrangement 818 also includes seven
torque-transmitting mechanisms 850, 852, 854, 856, 857, 858 and
859. The torque-transmitting mechanisms 850, 852, 854, 856, 857 and
858 are rotating type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanisms 859 is a
stationary-type torque transmitting mechanism, commonly termed
brake or reaction clutch.
[0145] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the planet carrier assembly member 846. The planet
carrier assembly member 826 is continuously connected with the ring
gear members 834 and 844 through the interconnecting member 870.
The sun gear member 822 is continuously connected with the
transmission housing 860.
[0146] The planet carrier assembly member 836 is selectively
connectable with the input shaft 17 through the clutch 850. The sun
gear member 832 is selectively connectable with the input shaft 17
through the clutch 852. The sun gear member 842 is selectively
connectable with the input shaft 17 through the clutch 854. The
ring gear member 824 is selectively connectable with the planet
carrier assembly member 836 through the clutch 856. The sun gear
member 832 is selectively connectable with the sun gear member 842
through the clutch 857. The sun gear member 832 is selectively
connectable with the planet carrier assembly member 846 through the
clutch 858. The planet carrier assembly member 836 is selectively
connectable with the transmission housing 860 through the brake
859.
[0147] The truth table shown in FIG. 9b defines the
torque-transmitting mechanism engagement sequence that provides the
reverse speed ratio and eight forward speed ratios shown in the
truth table and available with the planetary gear arrangement 818.
A sample of numerical values for the individual ratios is also
given in the truth table of FIG. 9b. These numerical values have
been calculated using the ring gear/sun gear tooth ratios also
given by way of example in FIG. 9b. The N.sub.R1/N.sub.S1 value is
the tooth ratio of the planetary gear set 820; the
N.sub.R2/N.sub.S2 value is the tooth ratio of the planetary gear
set 830; and the N.sub.R3/N.sub.S3 value is the tooth ratio of the
planetary gear set 840. FIG. 9b also describes the ratio steps
between adjacent forward ratios and between the reverse and first
forward ratio.
[0148] The powertrain 910, shown in FIG. 10a, includes the
conventional engine 12, a planetary transmission 914, and the
conventional final drive mechanism 16. The engine 12 is drivingly
connected with the planetary transmission 914 through the input
shaft 17. The planetary transmission 914 is drivingly connected
with the final drive mechanism 16 through the output shaft 19. The
planetary transmission 914 includes a planetary gear arrangement
918 that has a first planetary gear set 920, a second planetary
gear set 930, and a third planetary gear set 940.
[0149] The planetary gear set 920 includes a sun gear member 922, a
ring gear member 924, and a planet carrier assembly 926. The planet
carrier assembly 926 includes a plurality of pinion gears 927 that
are rotatably mounted on a carrier member 929 and disposed in
meshing relationship with the sun gear member 922 and the ring gear
member 924, respectively.
[0150] The planetary gear set 930 includes a sun gear member 932, a
ring gear member 934, and a planet carrier assembly member 936. The
planet carrier assembly member 936 includes a plurality of pinion
gears 937 rotatably mounted on a carrier member 939 and disposed in
meshing relationship with both the ring gear member 934 and the sun
gear member 932.
[0151] The planetary gear set 940 includes a sun gear member 942, a
ring gear member 944, and a planet carrier assembly member 946. The
planet carrier assembly member 946 includes a plurality of pinion
gears 947 rotatably mounted on a carrier member 949 and disposed in
meshing relationship with both the sun gear member 942 and the ring
gear member 944.
[0152] The planetary gear arrangement 918 also includes seven
torque-transmitting mechanisms 950, 952, 954, 956, 957, 958 and
959. The torque-transmitting mechanisms 950, 952, 954, 956, 957 and
958 are rotating-type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanism 959 is a
stationary-type torque-transmitting mechanism, commonly termed
brake or reaction clutch.
[0153] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 944. The ring gear member 924
is continuously connected with the planet carrier assembly member
936 and the sun gear member 942 through the interconnecting member
970. The sun gear member 922 is continuously connected with the
transmission housing 960.
[0154] The planet carrier assembly member 936 is selectively
connectable with the input shaft 17 through the clutch 950. The sun
gear member 932 is selectively connectable with the input shaft 17
through the clutch 952. The planet carrier assembly member 946 is
selectively connectable with the input shaft 17 through the clutch
954. The planet carrier assembly member 926 is selectively
connectable with the ring gear member 934 through the clutch 956.
The ring gear member 934 is selectively connectable with the planet
carrier assembly member 946 through the clutch 957. The ring gear
member 934 is selectively connectable with the ring gear member 944
through the clutch 958. The ring gear member 934 is selectively
connectable with the transmission housing 960 through the brake
959.
[0155] The truth table of FIG. 10b describes the
torque-transmitting mechanism engagement sequence utilized to
provide two reverse speed ratios and eight forward speed ratios, as
well as extra second and third forward speed ratios. The truth
table also provides a set of examples for the ratios for each of
the reverse and forward speed ratios. These numerical values have
been determined utilizing the ring gear/sun gear tooth ratios given
in FIG. 10b. The N.sub.R1/N.sub.S1 value is the tooth ratio of the
planetary gear set 920; the N.sub.R2/N.sub.S2 value is the tooth
ratio of the planetary gear set 930; and the N.sub.R3/N.sub.S3
value is the tooth ratio of the planetary gear set 940.
[0156] A powertrain 1010, shown in FIG. 11a, includes the
conventional engine 12, a planetary transmission 1014, and the
conventional final drive mechanism 16. The engine is drivingly
connected with the planetary transmission 1014 through the input
shaft 17. The planetary transmission 1014 is drivingly connected
with the final drive mechanism 16 through the output shaft 19. The
planetary transmission 1014 includes a planetary gear arrangement
1018 that has a first planetary gear set 1020, a second planetary
gear set 1030, and a third planetary gear set 1040.
[0157] The planetary gear set 1020 includes a sun gear member 1022,
a ring gear member 1024, and a planet carrier assembly 1026. The
planet carrier assembly 1026 includes a plurality of pinion gears
1027 rotatably mounted on a carrier member 1029 and disposed in
meshing relationship with both the sun gear member 1022 and the
ring gear member 1024.
[0158] The planetary gear set 1030 includes a sun gear member 1032,
a ring gear member 1034, and a planet carrier assembly member 1036.
The planet carrier assembly member 1036 includes a plurality of
pinion gears 1037 rotatably mounted on a carrier member 1039 and
disposed in meshing relationship with both the ring gear member
1034 and the sun gear member 1032.
[0159] The planetary gear set 1040 includes a sun gear member 1042,
a ring gear member 1044, and a planet carrier assembly member 1046.
The planet carrier assembly member 1046 includes a plurality of
pinion gears 1047 rotatably mounted on a carrier member 1049 and
disposed in meshing relationship with both the ring gear member
1044 and the sun gear member 1042.
[0160] The planetary gear arrangement 1018 also includes seven
torque-transmitting mechanisms 1050, 1052, 1054, 1056, 1057, 1058
and 1059. The torque-transmitting mechanisms 1050, 1052, 1054,
1056, 1057, 1058 and 1059 are all rotating-type torque-transmitting
mechanisms, commonly termed clutches.
[0161] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 1044. The ring gear member 1024
is continuously connected with the ring gear member 1034 and the
planet carrier assembly member 1036 through the interconnecting
member 1070. The sun gear member 1022 is continuously connected
with the transmission housing 1060.
[0162] The planet carrier assembly member 1026 is selectively
connectable with the input shaft 17 through the clutch 1050. The
sun gear member 1032 is selectively connectable with the input
shaft 17 through the clutch 1052. The planet carrier assembly
member 1036 is selectively connectable with the input shaft 17
through the clutch 1054. The planet carrier assembly member 1026 is
selectively connectable with the ring gear member 1044 through the
clutch 1056. The sun gear member 1032 is selectively connectable
with the ring gear member 1044 through the clutch 1057. The sun
gear member 1032 is selectively connectable with the sun gear
member 1042 through the clutch 1058. The planet carrier assembly
member 1036 is selectively connectable with the sun gear member
1042 through the clutch 1059.
[0163] The truth table shown in FIG. 11b describes the engagement
combinations and the engagement sequence necessary to provide the
reverse drive ratios and eight forward speed ratios, as well as an
extra seventh forward ratio. A sample of the numerical values for
the ratios is also provided in the truth table of FIG. 11b. These
values are determined utilizing the ring gear/sun gear tooth ratios
also given in FIG. 11b. The N.sub.R1/N.sub.S1 value is the tooth
ratio for the planetary gear set 1020; the N.sub.R12/N.sub.S2 value
is the tooth ratio for the planetary gear set 1030; and the
N.sub.R3/N.sub.S3 value is the tooth ratio for the planetary gear
set 1040. Also given in FIG. 11b is a chart describing the step
ratios between the adjacent forward speed ratios and the reverse to
first forward speed ratio.
[0164] A powertrain 1110, shown in FIG. 12a, includes the
conventional engine 12, a planetary transmission 1114, and the
conventional final drive mechanism 16. The engine is drivingly
connected with the planetary transmission 1114 through the input
shaft 17. The planetary transmission 1114 is drivingly connected
with the final drive mechanism 16 through the output shaft 19. The
planetary transmission 1114 includes a planetary gear arrangement
1118 that has a first planetary gear set 1120, a second planetary
gear set 1130, and a third planetary gear set 1140.
[0165] The planetary gear set 1120 includes a sun gear member 1122,
a ring gear member 1124, and a planet carrier assembly member 1126.
The planet carrier assembly member 1126 includes a plurality of
pinion gears 1127 rotatably mounted on a carrier member 1129 and
disposed in meshing relationship with both the sun gear member 1122
and the ring gear member 1124.
[0166] The planetary gear set 1130 includes a sun gear member 1132,
a ring gear member 1134, and a planet carrier assembly member 1136.
The planet carrier assembly member 1136 includes a plurality of
pinion gears 1137 rotatably mounted on a carrier member 1139 and
disposed in meshing relationship with both the sun gear member 1132
and the ring gear member 1134.
[0167] The planetary gear set 1140 includes a sun gear member 142,
a ring gear member 1144, and a planet carrier assembly member 1146.
The planet carrier assembly member 1146 includes a plurality of
pinion gears 1147 rotatably mounted on a carrier member 1149 and
disposed in meshing relationship with the ring gear member 1144 and
the sun gear member 1142.
[0168] The planetary gear arrangement 1118 also includes seven
torque-transmitting mechanisms 1150, 1152, 1154,1156, 1157, 1158
and 1159. The torque-transmitting mechanisms 1150, 1152, 1154,
1156, 1157 and 1158 are rotating type torque-transmitting
mechanisms, commonly termed clutches. The torque-transmitting
mechanism 1159 is a stationary-type torque-transmitting mechanism,
commonly termed brake or reaction clutch.
[0169] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 1144. The planet carrier
assembly member 1126 is continuously connected with the ring gear
member 1134 and the sun gear member 1142 through the
interconnecting member 1170. The ring gear member 1124 is
continuously connected with the transmission housing 1160.
[0170] The planet carrier assembly member 1146 is selectively
connectable with the input shaft 17 through the clutch 1150. The
sun gear member 1132 is selectively connectable with the input
shaft 17 through the clutch 1152. The sun gear member 1122 is
selectively connectable with the sun gear member 1132 through the
clutch 1154. The sun gear member 1122 is selectively connectable
with the planet carrier assembly member 1136 through the clutch
1156. The planet carrier assembly member 1146 is selectively
connectable with the sun gear member 1142 through the clutch 1157.
The planet carrier assembly member 1136 is selectively connectable
with the planet carrier assembly member 1146 through the clutch
1158. The planet carrier assembly member 1146 is selectively
connectable with the transmission housing 1160 through the brake
1159.
[0171] The truth table shown in FIG. 12b describes the engagement
combinations and the engagement sequence necessary to provide two
reverse drive ratio and nine forward speed ratios, as well as an
extra second forward speed ratio. A sample of the numerical values
for the ratios is also provided in the truth table of FIG. 12b. The
values are determined utilizing the ring gear/sun gear tooth ratios
also given in FIG. 12b. The N.sub.R1/S.sub.R1 value is the tooth
ratio of the planetary gear set 1120; the N.sub.R2/S.sub.R2 value
is the tooth ratio of the planetary gear set 1130; and the
N.sub.R3/S.sub.R3 value is the tooth ratio of the planetary gear
set 1140. Also given in FIG. 12b is a chart describing the step
ratios between the adjacent forward speed ratios and the reverse to
first forward speed ratio. For example, step ratio between the
first and second forward speed ratios is 2.33.
[0172] A powertrain 1210, shown in FIG. 13a, includes the
conventional engine 12, a planetary transmission 1214, and the
conventional final drive mechanism 16. The engine is drivingly
connected with the planetary transmission 1214 through the input
shaft 17. The planetary transmission 1214 is drivingly connected
with the final drive mechanism 16 through the output shaft 19. The
planetary transmission 1214 includes a planetary gear arrangement
1218 that has a first planetary gear set 1220, a second planetary
gear set 1230, and a third planetary gear set 1240.
[0173] The planetary gear set 1220 includes a sun gear member 1222,
a ring gear member 1224, and a planet carrier assembly member 1226.
The planet carrier assembly member 1226 includes a plurality of
pinion gears 1227 rotatably mounted on a carrier member 1229 and
disposed in meshing relationship with both the ring gear member
1224 and the sun gear member 1222.
[0174] The planetary gear set 1230 includes a sun gear member 1232,
a ring gear member 1234, and a planet carrier assembly member 1236.
The planet carrier assembly member 1236 includes a plurality of
pinion gears 1237 rotatably mounted on a carrier member 1239 and
disposed in meshing relationship with the ring gear member 1234 and
the sun gear member 1232.
[0175] The planetary gear set 1240 includes a sun gear member 1242,
a ring gear member 1244, and a planet carrier assembly member 1246.
The planet carrier assembly member 1246 includes a plurality of
pinion gears 1247 rotatably mounted on a carrier member 1249 and
disposed in meshing relationship with both the sun gear member 1242
and the ring gear member 1244.
[0176] The planetary gear arrangement 1218 also includes seven
torque-transmitting mechanisms 1250, 1252, 1254, 1256, 1257, 1258
and 1259. The torque-transmitting mechanisms 1250, 1252, 1254, 1256
and 1257 are rotating type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanisms 1258 and 1259
are stationary type torque-transmitting mechanisms, commonly termed
a brakes or reaction clutches.
[0177] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the planet carrier assembly member 1246. The sun
gear member 1222 is continuously connected with the ring gear
member 1234 and the sun gear member 1242 through the
interconnecting member 1270. The planet carrier assembly member
1226 is continuously connected with the transmission housing
1260.
[0178] The sun gear member 1232 is selectively connectable with the
input shaft 17 through the clutch 1250. The ring gear member 1244
is selectively connectable with the input shaft 17 through the
clutch 1252. The ring gear member 1224 is selectively connectable
with the planet carrier assembly member 1246 through the clutch
1254. The planet carrier assembly member 1236 is selectively
connectable with the ring gear member 1244 through the clutch 1256.
The planet carrier assembly member 1236 is selectively connectable
with the planet carrier assembly member 1246 through the clutch
1257. The sun gear member 1232 is selectively connectable with the
transmission housing 1260 through the brake 1258. The planet
carrier assembly member 1236 is selectively connectable with the
transmission housing 1260 through the brake 1259.
[0179] The truth table shown in FIG. 13b describes the engagement
combinations and the engagement sequence necessary to provide the
reverse drive ratio and eight forward speed ratios, as well as an
extra seventh forward speed ratio. A sample of the numerical values
for the ratios is also provided in the truth table of FIG. 13b.
These values are determined utilizing the ring gear/sun gear tooth
ratios also given in FIG. 13b. The N.sub.R1/S.sub.R1 value is the
tooth ratio of the planetary gear set 1220; the N.sub.R2/S.sub.R2
value is the tooth ratio of the planetary gear set 1230; and the
N.sub.R3/S.sub.R3 value is the tooth ratio of the planetary gear
set 1240. Also given in FIG. 13b is a chart describing the step
ratios between the adjacent forward speed ratios and the reverse to
first forward speed ratio.
[0180] A powertrain 1310, shown in FIG. 14a, includes the
conventional engine and torque converter 12, a planetary
transmission 1314, and the conventional final drive mechanism 16.
The engine and torque converter are drivingly connected with the
planetary transmission 1314 through the input shaft 17. The
planetary transmission 1314 is drivingly connected with the final
drive mechanism 16 through the output shaft 19. The planetary
transmission 1314 includes a planetary gear arrangement 1318 that
has a first planetary gear set 1320, a second planetary gear set
1330, and a third planetary gear set 1340.
[0181] The planetary gear set 1320 includes a sun gear member 1322,
a ring gear member 1324, and a planet carrier assembly 1326. The
planet carrier assembly 1326 includes a plurality of pinion gears
1327 rotatably mounted on a carrier member 1329 and disposed in
meshing relationship with both the sun gear member 1322 and the
ring gear member 1324.
[0182] The planetary gear set 1330 includes a sun gear member 1332,
a ring gear member 1334, and a planet carrier assembly member 1336.
The planet carrier assembly member 1336 includes a plurality of
pinion gears 1337 rotatably mounted on a carrier member 1339 and
disposed in meshing relationship with both the ring gear member
1334 and the sun gear member 1332.
[0183] The planetary gear set 1340 includes a sun gear member 1342,
a ring gear member 1344, and a planet carrier assembly member 1346.
The planet carrier assembly member 1346 includes a plurality of
pinion gears 1347 rotatably mounted on a carrier member 1349 and
disposed in meshing relationship with both the sun gear member 1342
and the ring gear member 1344.
[0184] The planetary gear arrangement 1318 also includes six
torque-transmitting mechanisms 1350, 1352, 1354, 1356, 1358 and
1359. The torque-transmitting mechanisms 1350, 1352, 1354, 1356 and
1357 are rotating-type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanisms 1358 and 1359
are stationary type torque-transmitting mechanisms, commonly termed
a brakes or reaction clutches.
[0185] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the ring gear member 1324. The sun gear member 1322
is continuously connected with the ring gear member 1334 and the
planet carrier assembly member 1346 through the interconnecting
member 1370. The sun gear member 1332 is continuously connected
with the transmission housing 1360.
[0186] The planet carrier assembly member 1346 is selectively
connectable with the input shaft 17 through the clutch 1350. The
planet carrier assembly member 1326 is selectively connectable with
the input shaft 17 through the clutch 1352. The sun gear member
1342 is selectively connectable with the input shaft 17 through the
clutch 1354. The planet carrier assembly member 1326 is selectively
connectable with the planet carrier assembly member 1336 through
the clutch 1356. The planet carrier assembly member 1336 is
selectively connectable with the ring gear member 1344 through the
clutch 1357. The planet carrier assembly member 1326 is selectively
connectable with the transmission housing 1360 through the brake
1358. The ring gear member 1344 is selectively connectable with the
transmission housing 1360 through the brake 1359.
[0187] The truth table shown in FIG. 14b describes the engagement
combinations and the engagement sequence necessary to provide three
reverse drive ratios and eight forward speed ratios. A sample of
the numerical values for the ratios is also provided in the truth
table of FIG. 14b. These values are determined utilizing the ring
gear/sun gear tooth ratios also given in FIG. 14b. The
N.sub.R1/N.sub.S1 value is the tooth ratio for the planetary gear
set 1320; the N.sub.R2/N.sub.S2 value is the tooth ratio for the
planetary gear set 1330; and the N.sub.R3/N.sub.S3 value is the
tooth ratio for the planetary gear set 1340. Also given in FIG. 14b
is a chart describing the step ratios between the adjacent forward
speed ratios and the reverse to first forward speed ratio.
[0188] A powertrain 1410, shown in FIG. 15a, includes the
conventional engine and torque converter 12, a planetary
transmission 1414, and the conventional final drive mechanism 16.
The engine and torque converter are drivingly connected with the
planetary transmission 1414 through the input shaft 17. The
planetary transmission 1414 is drivingly connected with the final
drive mechanism 16 through the output shaft 19. The planetary
transmission 1414 includes a planetary gear arrangement 1418 that
has a first planetary gear set 1420, a second planetary gear set
1430, and a third planetary gear set 1440.
[0189] The planetary gear set 1420 includes a sun gear member 1422,
a ring gear member 1424, and a planet carrier assembly 1426. The
planet carrier assembly 1426 includes a plurality of pinion gears
1427 rotatably mounted on a carrier member 1429 and disposed in
meshing relationship with the ring gear member 1424 the sun gear
member 1422.
[0190] The planetary gear set 1430 includes a sun gear member 1432,
a ring gear member 1434, and a planet carrier assembly member 1436.
The planet carrier assembly member 1436 includes a plurality of
pinion gears 1437 rotatably mounted on a carrier member 1439 and
disposed in meshing relationship with both the sun gear member 1432
and the ring gear member 1434.
[0191] The planetary gear set 1440 includes a sun gear member 1442,
a ring gear member 1444, and a planet carrier assembly member 1446.
The planet carrier assembly member 1446 includes a plurality of
pinion gears 1447, 1448 rotatably mounted on a carrier member 1449
and disposed in meshing relationship with the ring gear member 1444
and the sun gear member 1442, respectively.
[0192] The planetary gear arrangement 1418 also includes seven
torque-transmitting mechanisms 1450, 1452, 1454, 1456, 1457, 1458
and 1459. The torque-transmitting mechanisms 1450, 1452, 1454, 1456
and 1457 are rotating-type torque-transmitting mechanisms, commonly
termed clutches. The torque-transmitting mechanisms 1458 and 1459
are stationary type torque-transmitting mechanisms, commonly termed
a brakes or reaction clutches.
[0193] The input shaft 17 is not continuously connected with any
planetary gear member. The output shaft 19 is continuously
connected with the planet carrier assembly member 1446. The planet
carrier assembly member 1426 is continuously connected with the
ring gear member 1434 and the sun gear member 1442 through the
interconnecting member 1470. The sun gear member 1422 is
continuously connected with the transmission housing 1460.
[0194] The sun gear member 1432 is selectively connectable with the
input shaft 17 through the clutch 1450. The ring gear member 1444
is selectively connectable with the input shaft 17 through the
clutch 1452. The ring gear member 1424 is selectively connectable
with the planet carrier assembly member 1436 through the clutch
1454. The planet carrier assembly member 1446 is selectively
connectable with the sun gear member 1442 through the clutch 1456.
The planet carrier assembly member 1436 is selectively connectable
with the ring gear member 1444 through the clutch 1457. The ring
gear member 1424 is selectively connectable with the transmission
housing 1460 through the brake 1458. The planet carrier assembly
member 1436 is selectively connectable with the transmission
housing 1460 through the brake 1459.
[0195] The truth table shown in FIG. 15b describes the engagement
combinations and the engagement sequence necessary to provide the
reverse drive ratio and the eight forward speed ratios, as well as
an extra second forward ratio. A sample of the numerical values for
the ratios is also provided in the truth table of FIG. 15b. These
values are determined utilizing the ring gear/sun gear tooth ratios
also given in FIG. 15b. The N.sub.R1/N.sub.S1 value is the tooth
ratio for the planetary gear set 1420; the N.sub.R2/N.sub.S2 value
is the tooth ratio for the planetary gear set 1430; and the
N.sub.R3/N.sub.S3 value is the tooth ratio for the planetary gear
set 1440. Also given in FIG. 15b is a chart describing the step
ratios between the adjacent forward speed ratios and the reverse to
first forward speed ratio.
[0196] While the best modes for carrying out the invention have
been described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *